Foundation structure



June 26, 1945.

l R FREEMAN FoUNpA'TIoN STRUCTURE Filed Jan. 2e,l 1945 Patented June 26,1945 UNITED sTATEs PATENT OFFICE FUNDATION STRUCTURE Thomas RichardFreeman, si. Louis, M0.l

Application January 26, 1945, Serial No. 574,647

(Cl. 61-51) v 15 Claims.

This invention relates generally to foundation structures foi buildingsandthe like, and has particular reference to improvements in means andmethods for raising foundations which have dropped or settled because oferosion or faulty sub-soil condition, for stabilizing foundations andthe soil adjacent thereto to prevent slippage and settling, and foreffecting lateral displacement or replacement of foundation walls andcolumns.

The present invention entails the hydraulic injection into the ground ofa plastic, settable composition which functions to exert an elevatingforce on a wall, floor or column to be raised or stabilized, and to llcracks and voids in' and to harden the sub-soil for purposes ofpreventing erosion and soil-slippage in the regions about and underfloors and footings.

The hydraulic injection of a filling material for soil stabilizationpurposes has heretofore been known and practiced, chiefly in connectionwith highway maintenance where the method is used for raising concretepaving slabs which have sunk below the normal grade. In the past severalyears the so-called mud-injection process has been em.

ployed, with indilferent results, for stabilizing the foundations ofbuildings and to prevent the further settling of buildings where suchcondition has been found to exist. In using the process for foundationstabilization the practice has been to bore a series of holes into theground to a depth a substantial distance below the foundation footing,the series extending along the foundation wall, spaced to the outside ofand away from the wall a distance of three or four feet. A mixture ofmud and cementl is then injected into the holes to ll voids and crevicescaused by water erosion or the drying and shrinking of the soil, and,when possible, to compress the soil against the footing. The method hasmet with some success for the stated purpose where the faulty soilcondition is not due to subterranean water erosion, but where suchcondition exists the described method cannot be relied upon. Althoughthe raising of sunken paving slabs has for years been successfullypracticed by injecting a mud composition below the slab, the describedmethods heretofore prevailing are not adapted to the raising of thevfoundations and walls of buildings. One reason for this is that thelifting forces cannot be localized or confined tothe precise areas ofthe foundation where lift is desired, since the flowing mud may find alow resistance path and spread to other areas of the foundation, toexert a lifting force thereon at a point where such would be damaging.Since by former methods it is impossible to maintain uniform the liftingforces at definite points along a foundation wall, there is producedinternal stresses that tend to fracture the foundation and producecracks in the masonary wall which it supports.

The chief object and purpose of the present invention is to provide asimple, inexpensive'and highly satisfactory method for raising orrestoring to an original location, foundation structures which havebecome displaced due to faulty subsoil conditions, to stabilize suchfoundation structures and to effect a permanent support therefor so thatthey will remain in their normal or restored positions irrespective ofshifts, slippage or erosion of the adjacent soil.

Several example of means and methods for putting into practical eifectthe teachings of my invention are set forth in the followingdescription, wherein reference is made to the accompanying drawing. Insuch drawing,

Fig. 1 is a sectional elevational view of a foundation wall, showing avertical bore in the earth adjacent the wall, the provision of whichbore constitutes an early step in the method;

Fig. 2 is a plan View showing the location and spaced arrangement of aplurality of bores along the foundation Wall;

Fig. 3 is a sectional elevational View illustrating the lifting andsupporting installation at a later stage in the method;

Fig. 4 is a sectional elevational view illustrating the manner in whichthe method of my invention is employed to produce lateral displacementor replacement of a. foundation wall, and

Fig. 5is a sectional view of the lower end of the bore, illustrating afitting which is preferably employed to facilitate the method.

Describing now the means and method of my invention in detail, referencenumeral l0 designates a concrete foundation wall having the customaryfooting Il. Closely adjacent to the foundation and preferably located atthe outer side thereof so as to clear the footing, there is formed avertical bore l2 which may be produced by a hand or power-driven earthauger known and available to the trade. The bore l2 extends downwardlybelow the footing Il to a -depth which will be determined by thecharacter been found suitable. Where a wall or other extended structureis to be raised or stabilized a series of such bores suitably spacedalong the wall are provided as shown in Fig. 2.

After the bore or bores I2 have been drilled the auger is removed and acut is made in the side of each bore to produce a cavity I3 immediatelybelow the foundation footing II, a suitable tool having an off-setdigging head being employed for this purpose.

Thereafter, a length of pipe I4 is` inserted vertically in and centrallyof the bore as shown in Fig. 3, such pipe being of sufficient length toextend from the bottom of the bore to a point above the ground level,the pipe having a joint located a short distance below the groundleveland the sections being connected together by a threaded sleeve couplingor'pipe nipple I5. The

upper pipe section, designated I4 isprovided at its upper end with anelbow joint tting I6 to' facilitate connection with a pumping device,and with a cut-off valve I'I the purposes for which will also besubsequently explained. At its lower end pipe I4 is preferably providedwitha dished or bell-shaped flange-like fitting I8, screw-threadedthereto. This `member is of diameter slightly less than that of the boreto facilitate placing it at the bottom thereof, and serves to centralizethe lower end of the pipe in the bore.A Flange I8 serves the furtherimportant function of holding the pipe end out of contact with bottom ofthe hole, which otherwise would tend to obstruct the egress of mud orother composition-employed in the process in the manner to behereinafter explained. Although the size of the pipe I4 is not critical,a two inch diameter pipe has Abeen found to be well suited for use wherethe bore is eight inches in diameter as heretofore recommended, suchsize permitting the plastic composition to flow-.therethroughwithoutunduerestriction; and in other respects adequately fulfills-thepurpose of reinforcing the column to be cast aroundit. Suitablereinforcing-means in the Ioffset cavity I3 are provided, desirablyconsisting-of appropriately bent pieces I9 of steel-reinforcingrod-which may be initially held iniplace by securementv to the pipe I4as by wireties or the like.-l

The space around the pipeI4 within the bore I2, and the cavity I3 isfilled with cement, as appears in Fig. 3,'the-cement filling extendingupwardly to `a-point above the foundation footing and preferably belowthe ground level.V Before proceeding fur-ther the-cement is allowed toset. Thereis thus produced a `concrete column Y2l), having anintegral,-reinforcedl-corbelor bracket 2I subjacent the foundationfooting, the vcolumn being reinforced by the pipe I4 -which a'l'soserves to provide a central fluid passage that extends longitudinallycompletely therethrough.

The described installationis now ready for the lifting and stabilizingphasesl ofthe process. These are carried. out byinjecting, .by suitablepumping apparatus, a plastic, hard-setting composition into the upperend of'pipe I4. SuchV an apparatusy indicated generally at 2| infFig; 3,is known in the trade as a mud-jack. Y Its particular construction doesnot 'comprise la part ofy the present invention andanyrsuitablehydraulic apparatus adapted to. exertssuiicientpressure on theplasticcomposition to Vcause it to flow through the column 20 will servethepurpose. The device illustrated may briefly be describedfor.pur-poses of completeness as including 1a `hopper..22, the bottom Yofwhich slopes toward one end and. there communicates with a pumping.chamberv or cylinder 23 containing a reciprocating power-driven pistonor plunger 24. The pumping chamber discharges into a horizontal pipesection 25 which is connectedto the cut-off valve I'I and through thatmember to the pipe section I4-.

A composition found suitable for injection into and through the columnis made by mixing loose top soil or silty loam, comparatively free fromsand, with water to form a thin mud. A small percentage of cement (about5%) is added for setting purposes and to reduce shrinkage of the mud.

This composition is injected into the pipe I4 with suflicient pressureto cause it to flow through and out of the lower end of the column. Themixture is thus caused to ll all voids and fissures which may exist inthe vicinity of the base of the column. After such openings have beenlled, by continued pumping the hydraulic pressure on the lower end ofthe column exerts a lifting force which gradually raises the column, andwith it the foundation resting on the bracket portion 2|. When thestructure has been raised to the desired level the valve I'I is closedso as to trap and coniine the mud composition under pressure within andbelow the column. Following the elapse of sufficient time to allow themud composition to harden the pipe section I4 is disconnected atthejoint I5 and removed from the column; thereafter, the cavity remainingabove the column is filled with soil up to the ground level. l

Where a foundation wall is to be raised .by the described process bymeans of a series of columns in the manner suggested by Fig. 2, suitabletransverse piping 28 is provided to connect the upper ends of all of thecolumn passages, and the mud composition is pumped through the columnssimultaneously, so that equal lifting forces and uniform upwarddisplacement of the columns will result. A valve 29 serves to maintainthev mud composition under pressure during the setting period.

It will be understood that the mud composition spreads outwardly from orat the lower ends oi thecolumns and produces an effective base orfooting for these supports. It will further appear that the liftingforces on the foundation structure are definitely confined to thebearing areas afforded by the bracket portions 2l and the operator is infull and complete control of the acting forces, in degree and points ofapplication.

The method for effecting lateral displacement of a wall or other support29 is illustrated in Fig. 4 and in general accords with the methodpreviously described. In this case an opening 30 of size sufcient toreceive a workman is made in the ground adjacent thesupporting structureto the depthl of the base thereof. Next, a horizontal bore 3l leadingfrom the opening 30 is .made by'suitable boring tools. Piping 32 and 33leading from the base end of the bore to a valve 34 and a mud-jack isinstalled, and the bore v3I is filled about the pipe 32 with concrete toprovide a strut member 35, as shown. Thereafter, `mud composition ispumped through the piping to effect displacement of the concrete strut35 and foundation structure 29 in the manner explained inl connection`with Figure 3. Where a foundation member ,of substantial depth isencountered, requiring lateral displacement, the provision of additionalhorizontal concrete struts located at varying levels below the grade, isrecommended in order to .reduce bending stresses, in the foundation. Insuch case the fluid passages through the strutsv are interconnected bysuitable piping as suggested by Fig. 2, and the struts are pumpedsimultaneously in the manner and for the purpose heretofore mentioned.

I have described my invention with reference to several examples settingforth preferred methods of putting it into practical use. It will beunderstood that the invention is not confined to the particular methodsand uses described herein, and is not intended to be so limited.

What I claim and desire to secure by Letters Patent is:

1. The method of raising and stabilizing a building foundation whichcomprises installing a hollow column vertically in the earth insupporting relation to the building foundation, forcing hrm-settingfluid material through and out of the lower end of said column toelevate said column and foundation bythe hydraulic pressure at the lowerend of said column, and allowing said material to set while maintainedunder pressure.

2. The method of shoring a building foundation which comprisesinstalling a hollow, openended column reaching downwardly to asubstantially unyielding sub-strata of the earth, in supporting relationto said foundation, forcing firm-setting fluid material into and throughsaid column untilhydraulic pressure at the lower end is suihcient toraise the column, and maintaining said pressure while said fluid sets.

3. The method of shoring a building foundation which comprisesinstalling a hollow, openended column in the earth adjacent saidfoundation and in supporting relation thereto, with the open lower endof said column reaching downwardly to a substantially unyieldingsubstrata of the earth, forcing a firm-setting fluid material throughand out of the lower end of said column until hydraulic pressure at saidlower end is sufficient to raise the column, and maintaining saidhydraulic pressure during the setting of said material.

4. The method of shoring a foundation structure which comprises formingin the earth in supporting relation to said foundation a concrete columnhaving a fluid passage extending longitudinally therethrough, forcing afirm-setting fluid material through said passage to produce hydraulicpressure at the lower end sufficient to raise said column, andthereafter closing said passage to maintain said pressure during thesetting of said material.

5. The method of shoring a foundation which comprises forming in theearth adjacent the structure a hollow, open-ended concrete column havinga portion. thereof extending underneath said structure, forcingfirm-setting fluid material into the upper end, through, and out of thelower end of said column, and continuing the introduction of saidmaterial until hydraulic pressure at the lower end is sulcient to raisesaid column, and thereafter maintaining said pressure on the materialduring the setting thereof.

6. The method of raising a foundation structure which comprises formingin the earth adjacent said foundation a concrete column having alongitudinal fluid passage, and an integral bracket portion extendingsubjacent to said foundation structure, lling said passage withfirm-setting iiuid material, forcing additional of said material intosaid passage at its upper end so as to create hydraulic pressure on thelower end of said column sufficient to raise the column and foundationstructure therewith, and thereafter closing off said passage at itsupper end whereby to maintain said pressure during the setting of saidmaterial. Y

7. The method of raising afoundation structure which comprises forming abore in the earth adjacent said structure, excavating the earth belowsaid structure ito forma cavity communieating laterally with said bore,inserting a tubular reinforcing member-longitudinally within `the bore,filling said bore about said member and said cavity with concrete, andallowing said concrete to harden toproduce a supporting column,

forcing rm-setting-fluid material through and out of the lower end ofsaid tubular member whereby to effect a raising of saidcolumn andfoundation structure by hydraulic pressure at the lower end of thecolumn, and allowing said material to set while subjected to saidpressure.

8. The method of shoring and stabilizing a foundation structure whichcomprises installing a plurality of columnsv having. longitudinalpassages therethrough inthe earth, in supporting relation to thefoundation structure and spaced therealong, pumping firm-setting iiuidmaterial through said columns, simultaneously and at uniform pressure,whereby to provide uniform hydraulic pressure at the lower ends,sufficient to raise said columns, and maintaining said pressures duringthe setting of said iiuid material.

9. The hereindescribed method of raising and stabilizing a vfoundationstructure which comprises installing a plurality of columns havinglongitudinal, interconnected uid passages therethrough, in supportingrelation to and spaced along the foundation structure, pumpingfirmsetting fluid material into said passages whereby to produce uniformhydraulic pressure at the f lower ends sufficient to raise said columnssimultaneously, and allowing said material to set while subjected tosaid pressure.

10. The herein described method of raising a foundation structure whichcomprises forming a series of vertical bores in the earth, adjacent toand spaced along said foundation, excavating the earth at the sides ofsaid bores to form cavities immediately below the foundation, insertinglengths of pipe to extend longitudinally in said bores, substantiallythe full length thereof, filling the bores around said pipes and saidcavities with cement and allowing said cement to set, pumpingfirm-setting fluid material through said pipes simultaneously, toproduce uniform hydraulic pressure at the lower ends sufficient to raisesaid columns, and thereafter closing said passages to maintain saidpressure while said material hardens.

11. The herein described method of raising a foundation which comprisesforming a series of bores in the earth adjacent to and spaced along saidfoundation, excavating the earth at the sides of said bores to formcavities subjacent the foundation, inserting pipes longitudinally Withinthe bores, to extend substantially the full length thereof, insertingreinforcing means in said cavities, interconnecting said pipes, fillingsaid bores around said pipes and said cavities with cement and allowingsaid cement to harden, pumping a firm setting fluid composition throughsaid interconnected pipes, and out of the lower ends thereof, whereby toprovide uniform hydraulicv pressure at the lower ends of said columnssumcient to raise the same, and thereafter closing off said passages tomaintain said vpressure While said composition hardens.

12. The herein described method of moving a previously formed foundationstructure which comprises forming a bore intheearth thatextends awayfrom said foundation,;paralle1ito the direction .in which said;foundation is to. be moved, dsposingta pipe l.lengthwise insaid bore,filling said bore around saidpipe with concrete and lallori/'ing theconcrete to harden wherebyto form a hollow concrete'strut, pumpingafirmsetting fluid .material through .saidxstrut ,to .provide hydraulicpressure atth base ofzsaid strut sufficient to vmove thersamelongitudinally in the direction toward the foundation, and maintainingsaid pressure while :said materialhardens.

13. The method for moving-apreviously formed foundation structure whichcomprises forming aplurality of laterally spaced bores thatextend :fromsaidv foundation, parallelto the direction ,in which ithe foundation isto be moved, disposing pipeslengthwise iny said bores, interconnectingsaid pipes, filling 'said bores raroundsaidpipes with cement andallowingvsaid cement to harden, whereby to. produe a plurality of hollowconcrete struts, pumping firm-.setting fluid materia-l into and throughthe .interconnected pipeswhereby to provide uniform hydraulic pressureatthe base ends of said struts, sufficient .to move the samesimultaneously` in. the directiony toward the foundation, andthereaftermaintaining said hydraulic pressure while :said material `hardens.

14. The herein described methodfor leffecting lateral displacement ofv apreviously` formed foundation structure, which comprises forming a borein the` earth that 4extends substantially at rightangles to thefoundation structure, disposing a pipe lengthwise insaid bore,lling'said bore around said pipe witnconcrete andallowing said concreteto harden whereby to form a hollow strut, pumping a fluid, hrm-settingmaterial through said strut to provide hydraulic pressure at the baseend. thereof sufficient to move saidy strut and the foundation.therewith, and maintaining said pressure while said Vmaterial hardens. l

15. The herein described method for effecting lateral displacement vof apreviously Vformed foundation structure, which comprises excavating theearth to form a hole at 'one side of the .foundation structure,extending to the base thereof,` .form-.-

ing a bore in said earth extending from the bottom of said hole inadirection at .right angles to the foundation structure, disposing a pipelengthwise Within said bore, substantially the full length thereof,filling said bore ,around said pipe, and the bottom of said hole withconcrete and allowing said concrete to harden, whereby to produce a castin situ hollow concrete strut, pumping a uid, firm-setting materialthrough said strut and out of the base end thereof, whereby to providehydraulic pressure on the end of the strut sucient to move it lengthwisein the direction toward the foundation structure, andthereaftermaintaining said pressure while saidmatef-

